Vascular endothelial growth factor (VEGF) is a protein that stimulates vasculogenesis (i.e. de novo formation of new blood vessels) and angiogenesis (i.e. formation of new blood vessels from pre-existing vessels). There are at least six subtypes of VEGF, i.e. VEGF-A, VEGF-B, VEGF-C, VEGF-D, virus VEGF-E and placental VEGF (PIGF). VEGF-A is associated with increases of vascular permeability and degeneration of the extracellular matrix. Four isomers of VEGF-A that arise from alternative splicing of mRNA have been reported in humans (VEGF121, VEGF165, VEGF184, VEGF206) (Ferrara and Davis Smyth, Endocr Rev, 1997, 18:1-22). Further, VEGF110 is produced from VEGF165 by protease cleavage. VEGF-A binds to receptors VEGFr-1 and VEGFr-2 (Kajdaniuk et al., Endokrynol Pol, 2011, 62(5):444-55; Kajdaniuk et al., Endokrynol Pol, 2011, 62(5):456-64).
The specificity of VEGF action for endothelial cells supports a key role in the process of abnormal blood vessel growth and vascular leakage. Anti-VEGF agents have demonstrated efficacy in reducing choroidal neovascularisation in both animal models and clinical trials (Okamoto et al. (1997) Am J Pathol 151: 281-91; Adamis et al. (1996) Arch Ophthalmol, 114: 66-71). Specifically, anti-VEGF antibodies have been used for the treatment of treatments of intraocular neovascular disorders.
Currently available anti-VEGF antibodies are bevacizumab and ranibizumab. Bevacizumab is a full-length, humanized murine monoclonal antibody that recognizes all isoforms of VEGF. Ranibizumab is the Fab fragment of the humanized murine monoclonal antibody that is used to create bevacizumab and has been affinity-matured so that it binds VEGF-A with a significantly higher affinity than bevacizumab. Ranibizumab and bevacizumab appear to have similar efficacy profiles in the treatment of neovascular age-related macular degeneration although rare adverse events seem to occur more often with bevacizumab (Johnson and Sharma, Curr Opin Ophthalmol, 2013, 24(3):205-12).
Another class of VEGF antagonists is represented by fusion proteins of parts of the VEGF receptors and the Fc portion of human immunoglobulins. In particular, aflibercept, marketed under the name Eylea®, is a recombinant fusion protein consisting of the VEGF binding portion from the extracellular domains of human VEGF receptors 1 and 2 that are fused to the Fc portion of the human IgG1 immunoglobulin. It is approved for the treatment of wet macular degeneration and some further ocular diseases.
For medical purposes stable pharmaceutical compositions are of great interest, in particular ready-to-use solutions which require no dissolution or reconstitution before use. A main problem of such a liquid composition is a decreasing content of the active ingredient due to the formation of insoluble particles during repeated freeze/thaw cycles during manufacturing or proteins being degraded and forming degradation products during long-term storage.
WO 2006/104852A2 discloses liquid pharmaceutical formulations of aflibercept for subcutaneous or intravenous delivery which comprise a histidine buffer, sodium chloride, sucrose and polysorbate 20.
In particular for pharmaceutical compositions which are intended to be delivered to the eye, such as pharmaceutical compositions for intravitreal injections, it is important to keep the amount of insoluble particles at a minimum level, since particles may cause irritation or inflammation when injected into the eye.
US 2015/157709 A1 and US 2015/182623 A1 disclose formulations comprising a VEGF antagonist and anti-PDGF aptamer which are suitable for ophthalmological use. These formulations comprise a buffer with pH 5.0 to 8.0 and a tonicity modifier.
WO 2007/149334 A2 describes liquid pharmaceutical compositions of aflibercept comprising a sodium phosphate buffer, sodium chloride, sucrose and polysorbate 20 which formulations are suitable for ophthalmic use.
WO 2015/071348 A1 discloses liquid pharmaceutical formulations of ranibizumab for intravitreal injection comprising a buffer, a non-ionic surfactant, and, optionally, an inorganic salt, wherein the composition does not contain saccharides.
Nevertheless, there is still a need for a pharmaceutical composition which has a low protein aggregate content and is therefore suitable for intravitreal injection and which is stable in liquid form. Preferably, such a composition is suitable for the treatment of AMD and formulated in a prefilled syringe.